Gurusai Dutt retired from his work, he is related to

What is the chemical formula for common rust?

1. Fe3O4

2. FeO

3. Fe2O3 . xH2O

4. FeCL3

Vitamin necessary to prevent prolonged bleeding is 

Acid rain is caused due to pollution of the atmosphere by:

Deficiency of which of the following elements is responsible for weakening of bones?

1. Calcium 

2. Phosphorus

3. Nitrogen

Aromatic hydrocarbons contain at least how many benzene rings in their molecules?

Which endocrine gland requires iodine to synthesize a particular hormone, whose deficiency may cause goitre disease?

Which among the following form of coal contains the highest percentage of carbon content?

Bleaching powder is represented as ______.

What is the primary respiratory pigment in human blood?

Terylene is a condensation polymer of ethylene glycol and which acid?